Chapter 6: Photoelectrochemical Devices

Due to the global energy crisis, the PEC system has been widely explored since it was first adopted for water splitting in the year 1972. ZnO nanomaterials, with a direct band gap of 3.37 eV and high mobility of 210 cm² V⁻¹ s⁻¹, play an indispensable role in such solar-to-chemical energy conversion systems. This chapter focuses on the employment of ZnO nanostructures for the applications of PEC water splitting. We briefly describe recent trends in the construction of ZnO nanostructure photoelectrodes as well as performance enhancement protocols for PEC hydrogen evolution in terms of light absorption range extension, photo-induced charge carrier separation strengthening and photo-stability improvement. At present, it is crucial to solve the discussed bottleneck issues a breakthrough in such artificial photosynthesis system is highly expected in the foreseeable future.